Method and apparatus for cooling soap and the like



Jan. 8, 1957 A. L. SCHULERUD METHOD AND APPARATUS FOR COOLING SOAP AND THE LIKE Filed Dec. 30. 1952 INVENTOR o o 0 0 0 0 0 0 0 0 A b DAvbAVvAvbAvDOD D 0 m O O O o a 9000 oooowooowoi wol nowowonoonowowo o o o o o o o o 0 0 0 0 0 o 0 0 0 o owononononowonono 0 0 0 0 o u w w o o o 0 0 o o o 0 o o J/Jaly/elcfiakmd BY M ATTORNEY United States Patent METHOD AND APPARATUS FOR COOLING SOAP AND THE LIKE Albert Lyle Schulerud, Nutley, N. J., assignor to Colgate- Palmolive Company, Jersey City, N. J., a corporation of Delaware Application December 30, 1952, Serial N 0. 328,770

11 Claims. (Cl. 62-404) This invention relates to method and apparatus for the cooling of soap or the like, without appreciable drying of the surface thereof, and more particularly to a process and apparatus for continuously cooling cakes of soap fresh from a soap plodder preparatory to conditioning them for later treatment such as in an automatic power press of a type such as the conventional Jones soap press.

In conventional soap-making practice, it is customary, after cutting the soap from the plodding machine into cakes of approximately the desired size, to pass the more or less roughly-cut soap cakes to an automatic power press, such as a Jones soap press, where they are formed under heavy pressure into soap tablets bearing any desired indicia, such as the manufacturers name, trademark, etc. In the manufacture of toilet soap, which usually has a moisture content of about 15% or less,

the pressing offers no particular diflicultybut in manufacturing soaps of higher moisture content, either dense or floating types, a different situation obtains since the soap issuing from the plodder in these last mentioned types is relatively soft and warm due to the temperatures normally encountered in the plodding machine, and if processed immediately in the press it would adhere to the dies of the press and would soon prevent the operation thereof. Thereof the soap cannot immediately be pressed in the automatic press and it is necessary to permit the roughly-cut cakes of soap (still soft and warm by reason of the sensible heat of the soap mass as it comes from the plodding machine) to cool sufficiently so as to present relatively cool hard surfaces to the dies of the press to prevent fouling of the dies with the formation of imperfect soap tablets and eventual stoppage of the press.

In actual plant practice, the roughly-cut cakes formed from the mass of soap issuing from the plodding machine are frequently permitted to stand in suitable trays or racks until they have cooled substantially to room temperature at which time their surfaces become sulficiently hard to enable them to be passed through the automatic soap presses without interfering with the satisfactory operation of the presses. However, undesirable drying of the edges occurs in such atmospheric cooling and the time factor involved in thus permitting the normal atmospheric cooling of such soap cakes is undesirable in that the step increases the hold-up-time of soap in process and thus contributes to increased costs of manufacturing soap in finished form ready for market.

It is therefore an object of the present invention to provide a process and apparatus for handling soap or similar plastic material without appreciable drying or overdrying of the surfaces of the soap such as might be occasioned by subjecting the soap to blasts of warm or hot air. It is a further object of the invention to provide a continuous process that involves the use of simple apparatus for carrying out the step of cooling roughlycut cakes of soap still warm and soft as a result of a preceding plodding operation, thereby permitting this step to be carried out in such manner as largely to avoid the known disadvantages resulting from ordinary atmospheric cooling of such soap cakes while at the same time contributing new and unexpected advantages not heretofore appreciated.

The manner in which these and other objects of the invention are attained will become apparent from the following description which is intended to be illustrative rather than limitative.

According to the present invention, it has been discovered that the desired cooling of the roughly-cut cakes formed from the soap issuing from the plodding machine, and which soap is still warm and soft from the temperatures encountered in the plodding machine, may be brought about in a very convenient and eifective manner by contacting the warm soft cakes of soap with a liquid refrigerant under such conditions as to produce cool hard soapsurfaces. This step is followed immediately by the substantially complete removal of excess liquid refrigerant, usually in the form of droplets, from the soap surfaces by means of a strong current of a suitable gas such as air. More particularly, the present invention provides a method and apparatus by which these operations may be continuously and effectively carried on while the roughly-cut cakes of soap, still warm and soft from the heat of the plodding machine, are carried on a continuously moving belt surface through a series of suitable treating Zones in which the cooling and drying operations are carried out successively and without interruption. Due to the arrangement of the'several apparatus elements to be described hereinafter, it is possible to vary the rate of movement through the treating zones, the rate of treatment thereof with the refrigerant liquid, and the rate of treatment thereof with the cooling or drying stream of gas such as air.

The apparatus for carrying out the process according to the present invention is characterized by a continuously-moving endless belt which carries the warm soft cakes of soap from the cutting table through the treating zones, the endless belt being supported on suitable rollers. The belt on which the soap rests is made of mesh material through which the cooling liquid may flowafter it has contacted the soap. Beneath the refrigerant-soap contacting zone there is disposed a tank into which the spent cooling liquid flows and from which it is withdrawn, passed through a suitable heat exchanger to reduce its temperature to the desired extent, and then recycled to a series of suitable liquid distributing means such as sprays or nozzles located above the cooling section of the beltand from which the cooling liquid is forced in the form of sprays onto the warm soft cakes of soap passing thereunder. The soap cakes then pass through another section of the apparatus where residual refrigerant that has not already drained away by gravity is forcibly removed from the surfaces of the now-cooled soap cakes in any appropriate manner,'for example, by means of a blast of a suitable gas such as air. After this step the cakes of soap pass to the discharge end of the belt from which they may be removed as desired for further processing.

In order to illustrate still further the present invention, reference is made to the accompanying diagrammatic drawing illustrating a preferred embodiment of the invention. In this drawing, Figure 1 shows the apparatus in somewhat diagrammatic fashion, being a vertical longitudinal cross-section;

Figure 2 is a top plan view showing a portion of the endless belt and its supporting grid structure; and

Figure 3 is a vertical cross-section through the belt and -12 its supporting grid structure, taken along the line 3-3 of Figure 2.

Referring now to Figure 1, the apparatus consists of a continuously-moving endless belt supported between two rollers 12 and 14 situated at either end of the apparatus. As shown, the upper run of the belt moves in the direction from right to left of Figure l. The lower run of the belt 10 passes between drive rolls 16 and 18 which are driven by a suitable motor (not shown) at any predetermined speed. Suitable idler rollers such as 20, 22, 24, and 26 are provided in a manner known per se in order to assure the desired smooth operation of the belt 10. One or more of these, for example roller 20, may be adjustable in position in order to place a suitable tension on the belt 10.

The upper run of the belt 10 passes below a series of cooling liquid distributors such as spray nozzles 28 communicating by means of manifold 30 and line 32 with a source of refrigerant liquid, such as a brine solution, cooled to any desired temperature. Disposed below the upper run of the belt 10 is a tank 34 which serves to collect the spent refrigerant liquid that passes through the belt 10 after contacting the roughly-cut cakes of soap. The spent refrigerant liquid is removed from tank 34 via line 36 and thereupon forced by means of pump 38 through a suitable heat exchanger 40 where the spent refrigerant liquid is again cooled to the desired low temperature for recirculation through the apparatus via line 32, manifold 39 and nozzles 28.

Near the end of the upper run of the belt 10, adjacent the region where the belt leaves the refrigerant liquid contacting zone defined by the region below the spray nozzles 28, the belt passes through a gas-scrubbing section. Here a suitable gas, for example air, is introduced under pressure by conduit 42 which discharges through a series of nozzles 44. In this way a suitable gas, such as air, is forced to flow under considerable pressure over the roughly-cut cakes of soap after they have been treated in the liquid-cooling section of the apparatus.

The gas-scrubbing section of the apparatus is supplied with air forced into the conduit 42 from an air compressor unit 46, the inlet to which communicates via line 48 with a slotted chamber 50 disposed directly underneath the belt 10 and adjacent the brine tank 34, thereby being operative to remove by'suction the last traces of refrigerant liquid retained superficially on the lower surfaces of the cakes of soap as they pass over the slotted chamber. The compressor is preferably a Nash air compressor. This unit uses fresh water for a seal and, since the fresh water is continuously supplied and withdrawn, this protects the compressor from undue corrosion due to brine mist removed via line 48. Thus, there need be no direct connection between chamber 50 and the brine system.

If desired, a valved line 52 communicating with the air line 42 may be provided. Line 52 discharges air under pressure via nozzles 54 onto the lower run of the belt 10 as it reverses itself over the roller 14. In this manner the belt itself is substantially completely cleaned and at the same time any small particles of soap that might remain on the belt are blown into the hopper 56 from which they may be removed from time to time.

If desired, substantially the entire apparatus, but particularly the brine-treating section thereof, may be enclosed within a liquid-tight chamber to confine the spray of brine. This chamber is shown broken away in Figure 1, only a portion of the walls 58 being shown for the sake of clarity.

Referring now to Figures 2 and 3 for details of construction of the belt 10, this is preferably of mesh construction so as to permit spent refrigerant liquid to flow therethrough. It is supported during the course of its upper run on a stationary metal grid 60. The grid 60 in turn is supported at spaced intervals by a series of steel rails or cross-supports 62, which may conveniently take the form of angle irons as shown more clearly in Figure 1.

The endless belt 10 on which the cakes of soap rest is of mesh construction and is made of a suitable material capable of withstanding the action of the brine or other refrigerant liquid employed in the process. For example, it may conveniently be made of Saran mesh (12 X 12 mesh calendered) which is understood to be a copolymer of vinylidene chloride and vinyl chloride. Other plastic materials may be employed if desired.

The grid 69 that supports the belt 10 and the steel rails 62 that support the grid 60 may conveniently be coated with neoprene (polymerized chlorobutadiene) to impart the necessary corrosion resistance thereto. Other plastic materials may be employed if desired.

The rate of movement of the belt 10 through the apparatus may be varied at will, depending upon the operating conditions desired. For example, belt speeds varying from about 10 inches to 2 feet per minute have been found to be very satisfactory when treating cakes of soap which at the start were at a temperature of about F., employing brine temperatures of about 55 to 60 F., and a treating time in the brine cooling zone varying from about 8 to 20 minutes.

In one particular form of the apparatus, a Saran mesh belt 10 approximately 38 inches wide and having a horizontal run of 20 feet was employed, the horizontal belt area (i. e., the upper run of the belt) being divided into four sections. The first section was about 1% feet long and constituted the warm soap feed section or end; the next 16 feet constituted the spray or cooling section where cooled brine, having a gravity of about lB-l9 Be. and a temperature of about 60 F., was sprayed upon the roughly-cut cakes of soap as they passed through the cooling section; the next 1 to 1 /2 feet constituted an airscrubbing section Where air under. pressure was blown onto the cool wet cakes of soap and was then sucked through a slot under the belt to effect substantially con plete removal of the excess brine from the surfaces of the soap and the belt; while the final section constituting the balance of the belt was of course the discharge end of the belt where the cool dry cakes of soap were removed.

Referring again to Figure l, roughly-cut cakes of soap 70 from a cutting table were placed on a continuouslymoving endless belt 10 in rows. These rows of cakes were formed by cutting a plodder bar into the cake-sized pieces and moving the pieces forward in the same relative position in which they came through the cutting head, thus making in this particular instance 10 blank cases of soap moving abreast by means of the belt through the cooling apparatus.

The cakes of soap moved through the spray or cooling section where they were bathed by means of cold brine under the temperature conditions noted above, forced under pressure from 12 full square sprays 28, made of pure nickel or stainless steel, and set in two identical banks approximately 2 to 2% feet above the mesh Saran belt 10 in such a way that the sprays cover an area of the belt 16 feet long and 42 inches wide Without any dry spots. These sprays were operated at brine pressures of about 7 to 10 pounds gauge, but higher or lower pressures may be employed if desired. The cold brine issuing from the sprays contacts the soap cakes and flows over the surfaces thereof, through the mesh belt 10 and supporting grid structure 60 and into the tank 34 extending beyond the spray area in a horizontal direction in such fashion that all the runoff from the sprays is collected therein. This catchall tank 34 serves not only to collect the runoff from the sprays but also as a storage tank for the refrigerant system. The tank 34 is constructed of steel lined with neoprene.

From the bottom of the tank 34 spent brine flows via line 36 suitably fabricated of Satan. or other suitable corrosion-resistant material, to the pump 38 which circulates the brine at a pressure 'of about 10 pounds gauge through the system. The outlet of the pump 38 is connected by means of a Saran pipe to the heat-exchanger or cooler 40 of which all parts that contact the brine are constructed of a suitable corrosion-resistant material such ass nickel. Here the brine is cooled to a predetermined thermostatically-controlled temperature whereupon the cooled brine is returned via line 32, also of Saran, to the manifold 30 and spray nozzles 28. The line 30 and the spray nozzles 28 are also suitably fabricated of Saran or other corrosionresistant material.

The brine or other refrigerant liquid is cooled in the heat-exchanger 40 by means of a standard Freon refrigeration system, or by other means as may be desired.

The gas scrubbing section of the apparatus located beyond the brine scrubbing section, but preferably still within the housing or chamber 58 enclosing the apparatus, is so arranged as to deliver a uniform blast of clean air under considerable pressure through one or two banks of air nozzles 4-4 over the tops and sides of the still-Wet cakes of soap to remove standing brine droplets from the surfaces thereof. Any brine still tending to hang in the meshes of the belt and/or around the bottom edges of the soap cakes 70 after they pass immediately below the nozzles 44 is drawn through the slotted chamber 50 at the same time that the air sucked into the slotted chamber 59 is fed into the inlet of the air compressor unit 46 via line 48. If desired, additional air may be directed under pressure onto the lower run of the belt 10 by means of valved line 52 and nozzles 54, thereby conditioning the belt 10 and rendering it substantially clean before it completes the lower run and passes over the roller 12 at the feed end of the apparatus.

The cooled dried soap cakes may be removed from the discharge section of the belt 10 as it reaches the roller 14 by hand and placed in racks or trays ready for transport to the automaticsoap presses, or, if desired, the soap cakes may be discharged onto a conveyor belt which transports them directly to the press station. Similarly, the warm, soft freshly-cut cakes formed from the soap coming from the plodding machine may be introduced onto the feed end of the belt 10 as it passes over the roller 12 by hand or, if desired, the soap cakes may automatically be delivered thereto by a suitable conveyor belt.

As will be apparent to those skilled in the art, other brine densities, and hence other salt concentrations, may be employed, and if desired other refrigerant liquids may be employed in place of brine, depending upon the operating conditions encountered or desired. The brine or other refrigerant liquid may be cooled to still lower temperatures as it flows through the heat exchanger 40. It is only necessary to choose a coolant liquid, having regard to the nature of the solid plastic material to be cooled and hardened, such that the solid will be substantially insoluble in the coolant under the conditions of operation and such that the coolant does not have any adverse effect upon the solid plastic material to be cooled.

Instead of distributing the refrigerant liquid over the soap or other solid plastic material to be cooled from a series of sprays as illustrated in detail herein, it will be apparent that any other efiicient method of distributing the refrigerant liquid fairly uniformly over the material to be cooled may be employed, such as a cascade or cascades of trays, a slotted or other grid arrangement, or otherwise as desired.

It will be apparent from the foregoing description that the present invention provides a convenient method and apparatus for eifecting cooling without drastic drying of a warm, soft, solid material such as soap or the like plastic material without being so drastic as to have a permanent undesirable effect upon the surface characteristics of such material. Consequently the invention is well adapted for use in connection with the treatment of soap orsimilar plastic materials where mechanical difficulties due to the sticking of dies and other moving'metal parts would otherwise be encountered if adequate cooling were not employed on the one hand, or on the other hand where quality difficulties would be encountered due to drying of the edges and corners of the product by racking and air cooling. In the case of the treatment of soap to which this invention is primarily directed, the cooling arrangement herein provides the necessary cooling and drying without overdrying, i. e., without the formation of an undesirable overdried skin on the surface of the treated cakes of soap with consequent reduction in desirable physical properties of the soap, including its appearance.

Although the process and apparatus of the present invention have been described in connection with the treatment of warm, soft cakes of soap as the soap issues in that condition from a soap plodding machine, it will be apparent that the invention may also be applied to the treatment of other similar plastic solid materials which must be converted from a soft, warm state to a cold, dry state for further efficient handling or treatment thereof.

While specific examples of preferred methods and apparatus embodying the present invention have been described above, it will be apparent that many changes and modifications may be made therein without departing from the spirit of the invention. It will therefore be understood that the particular apparatus and methods of procedure set forth above are intended to be illustrative only and are not intended to limit the invention.

What is claimed is:

l. A method of cooling a plurality of cakes of soap still warm and soft from a precedent plodding operation comprising passing the cakes through a cooling zone where they are contacted with brine cooled to a temperature not over approximately 60 F. and immediately thereafter through a drying zone where they are contacted with a blast of air sufficient to remove drops of brine adhering to the surfaces of said cakes, thereby imparting to said cakes of soap cool, dry, relatively hard surfaces and conditioning them for subsequent pressing into soap tablets.

2. A method of cooling a plurality of roughly-cut cakes of soap that are still warm and soft from a precedent plodding operation performed upon the soap comprising passing said cakes of soap through a cooling zone and there contacting them with a cooling liquid, and thereafter passing said cakes through a gas scrubbing zone where they are contacted with a stream of gas under a pressure sufiicient to remove substantially all drops of cooling liquid adhering to the surfaces thereof.

3. A method of conditioning for pressing into soap tablets a plurality of roughly-cut cakes of soap that are still warm and soft from a precedent plodding operation comprising passing said cakes through a cooling zone and there contacting them with sprays of cold brine under conditions such as to cool and harden the surfaces of said cakes, and thereafter immediately passing said cakes through a gas scrubbing zone wherein they are contacted with a stream of gas under a pressure sufiicient to remove substantially all drops of brine adhering to the surfaces of said cakes.

4. A method of conditioning for pressing into soap tablets a plurality of roughly cut cakes of soap that are still warm and soft from a precedent plodding operation comprising passing said cakes through a cooling zone and there contacting them with sprays of brine having a temperature of not more than approximately 50 F. under conditions such as to cool and harden the surfaces of said cakes, and thereafter immediately passing said cakes through a scrubbing zone wherein they are contacted with blasts of air under a pressure and for a time sufficient to remove substantially all drops of brine adhering to the surfaces of said cakes without producing an overdried skin on said cakes.

meant-4 5. A method of handling freshly-cut cakes of soap that still retain substantial-sensible heat from a precedent plodding operation comprising introducing said cakes onto the surface of a continuouslyqnoving endless belt and while supported on said surface passing said cakes through a cooling zone in which they are contacted with a spray of cold brine, and thereafter, while still supported on said belt surface, passing said cakes through a gas scrubbing zone in which they are contacted with a stream of air under sufiicient pressure to substantially completely remove residual drops of brine adhering to the surfaces of said cakes.

for a subsequent tablet pressing operation a plurality of roughly-cut cakes of soap that still retain substantial sensible heat from a precedent plodding operation and which therefore are too soft to permit immediate pressing into finished tablets comprising introducing said cakes onto the surface of a continuously moving endless belt and while supported on said surface passing said cakes through a brine-treating zone in which they are contacted with a spray of cold brine having a temperature of not more than about 60 F., and thereafter, while still supported on said belt surface, passing said cakes through a gas scrubbing zone in which they are contacted with a stream of air under sutficient pressure to substantially completely remove residual drops of brine adhering to the surfaces of said cakes.

7. A method of handling freshly-cut cakes of soap that still retain substantial sensible heat from a precedent plodding operation comprising introducing said cakes onto a moving belt surface and while supported on said surface passing said cakes through a cooling zone in which they out sticking to the spent brine after it has contacted said cakes of soap, passing the spent brine through a heat-exchanger to cool it, and recycling the re-cooled brine to the cooling zone.

8. A method of cooling a plurality of bodies of warm soap comprising passing the warm soap bodies through a cooling zone where they are contacted with a cooling liquid and thereafter through a drying zone where they are contacted with a stream of gas under sufficient pressure to remove drops of cooling liquid adhering to the surfaces of said bodies, collecting the spent cooling liquid after contacting said bodies, passing the spent cooling liquid through a heat-exchanger to lower its temperature to a predetermined value, and then recycling the spent cooling liquid to the cooling zone.

9. A method as in claim 2 in which the spent cooling liquid is collected after contacting said cakes of soap, then passed through a heat-exchanger to lower its tem perature to a predetermined value, and then recycled to the cooling zone.

l0. A method as in claim 5 in which the spent brine is collected after contacting said cakes of soap, then passed through a heat-exchanger to lower its temperature to a predetermined value, and thcn recycled to the cooling zone.

ll. Apparatus for cooling and hardening plastic bodies such as soap and the like comprising means defining an moving them through successive treating zones, said endless belt being of mesh construction and having at least the surfaces thereof that contact the plastic bodies formed of an organic polymeric corrosion-resistant material, said endless belt in turn being supported on a metal grid which is coated with an organic plastic material characterized by corrosion-resistance to the cooling liquid, means adjacent said endless belt for contacting said bodies with a cooling liquid, means adjacent said endless belt for thereafter contacting said bodies with a stream of. gas for removing residual cooling liquid from said bodies, and means for collecting spent cooling liquid and recyciing same to said cooling means.

References Cited in the file of this patent UNITED STATES PATENTS Bell et al. Apr. 9, 1929 Dec. 17, 1929 

